JP2000202988A - Printing agent filling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly prevent a cream solder as a printing agent from becoming highly viscous and at the same time, prevent the solid component and the liquid component of the cream solder from being separated by excess stirring. SOLUTION: This printing agent filling device uses a filling member 1 having a stirring means which comprises a printing agent storage part 1a which stores a cream solder 50, a discharge aperture 1b for the cream solder 50, formed in a part coming into contact with a stencil mask, a replenishing aperture 1c which replenishes the solder 50 to the printing agent storage part 1a, a movable member 2 which stirs the solder 50 by transferring a part of the solder 50 tending to flow toward the discharge aperture 1b from the replenishing aperture 1c in the printing agent storage part 1a, in a different direction from a direction where the part of the solder 50 moves and the like. Further, a forcing-in means which forces the solder 50 from the replenishing aperture 1c of the filling member 1 into the printing agent storage part 1a, is provided independently of the stirring means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a printed object, such as an electronic circuit board or a surface-mounted component mounted on the board, on a printed surface of a printing mask used for printing on a printing surface. The present invention relates to a printing agent filling device for filling a printing agent such as a paste.

[0002]

2. Description of the Related Art Conventionally, the following two types of printing agent filling apparatuses of this type are known. First, a printing agent placed on the surface of the printing mask is moved into a through hole or a concave portion of the printing mask by moving a squeegee blade made of a plastic material or the like along the surface while pressing the squeegee blade against the surface of the printing mask. It is a rub-in type device that rubs and fills. Second, the printing material in the printing material container of the filling member is extruded from a discharge port surrounded by a pair of blades attached to the printing mask side of the printing material storage portion, and the filling member is removed. This is a press-fit type device in which the printing agent is filled in through holes or recesses of the print mask by moving along the surface of the print mask.

In the latter press-fit type device, a printing agent is forcibly pressed into a through hole or a concave portion of a print mask.
Even when the inner wall of the through hole or the concave portion of the print mask is rough, sufficient filling can be performed, and there is an advantage that adhesion to a pad on an electronic component such as a substrate can be promoted. In this press-fit type apparatus, for example, an inert gas is supplied to a closed container having a discharge port formed of a pair of squeegees or the like, and the printing agent in the closed container is supplied to the discharge port by the pressure of the inert gas and its own weight. What is supplied is known (see, for example, JP-A-4-284249).

[0004]

However, in the press-fit type apparatus disclosed in Japanese Patent Application Laid-Open No. 4-284249, the viscosity of the printing agent in the closed container gradually increases, and poor filling of the stencil mask into the through-holes occurs. There was a risk of occurrence. Therefore, as a device capable of preventing an increase in the viscosity of the printing agent in the printing agent storage portion, a printing agent is placed on a pair of squeegee sides in a housing structure corresponding to the printing agent storage portion that stores the printing agent. It is known to provide a cylindrical unit having a built-in kneading means also serving as a feeding means for feeding, and to prevent the viscosity of the printing agent from being increased by kneading the printing agent with the kneading means (for example, And JP-A-8-112289). However, in this apparatus, since the kneading unit also serves as the feeding unit, the kneading unit is continuously driven during printing, and liquefaction occurs due to excessive stirring of the printing agent, and the solid in the printing agent is generated. There is a possibility that the component (for example, solder particles) and the liquid component (for example, flux) may be separated.

Further, in order to prevent the viscosity of the printing agent in the printing agent container from increasing, a printing apparatus manufactured by MPM in the United States has a pair of squeegees in an inverted “C” shape so as to narrow the printing object side. And the printing agent container is configured to have an internal space close to a cylindrical shape, so that the printing agent exposed from the squeegee at the time of printing receives the printing agent by a shear stress received from the surface side of the printing mask. A filling device adapted to perform a circulating motion (rolling) in the section is employed. In this device, the circulation of printing agent (rolling)
To prevent the viscosity from being increased. However, the shear stress received from the stencil mask side seems to be too small to generate the circulating motion, and since the shear stress greatly changes depending on printing conditions such as printing speed, the viscosity of the printing agent is increased. Seems to be difficult to prevent.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the viscosity of a printing agent from being increased, and to reduce the solid component of the printing agent due to excessive stirring of the printing agent. It is an object of the present invention to provide a printing agent filling device capable of preventing separation of liquid and liquid components.

[0007]

According to one aspect of the present invention, there is provided a printing material filling apparatus for filling a printing material into a through hole or a concave portion of a printing mask, wherein the printing material is accommodated. A printing material container, a printing material discharge port formed at a portion where the printing material comes into contact with the printing mask, a supply port for replenishing the printing material storing portion with printing material, and the supply port in the printing material storing portion. A stirrer for moving a part of the printing agent moving toward the discharge port from the moving agent in a direction different from the moving direction of the printing agent to stir the printing agent. A press-fitting means for press-fitting the printing agent from the supply port of the member into the printing agent storage section is provided independently of the stirring means. In this printing material filling apparatus, by press-fitting the printing material into the printing material container from the supply port of the filling member by the press-fitting means, the printing material is discharged so as to be pushed out from the discharge port of the filling member to the print mask,
A printing agent is filled into the through holes or the concave portions of the print mask. And by the stirring means provided independently of the press-fitting means,
A part of the printing agent that is going to move from the supply port of the filling member toward the discharge port is moved in a direction different from the moving direction of the printing agent, and the printing agent in the printing agent container of the filling member is stirred, The viscosity of the printing agent in the printing agent container is prevented from increasing.

According to a second aspect of the present invention, in the printing agent filling apparatus of the first aspect, a movable member having an uneven surface and a driving device for driving the movable member are provided as the stirring means. Is what you do. In this printing material filling device, a part of the printing material that is moving from the supply port to the discharge port of the filling member is driven by driving the movable member having the unevenness on the surface by the driving device, so that the surface of the movable member is removed. The printing agent is moved in a direction different from the moving direction of the printing agent by the unevenness to stir the printing agent in the printing agent storage section of the filling member so that the viscosity of the printing agent in the printing agent storage section does not increase.

According to a third aspect of the present invention, in the printing material filling apparatus according to the second aspect, the movable member has irregularities in a direction intersecting a moving direction of the printing agent from the supply port to the discharge port of the filling member. A movable member having a repeatedly formed surface is provided so as to be reciprocally movable in a direction intersecting with a moving direction of the printing agent. In this printing material filling device, the printing material that moves from the replenishing port of the filling member toward the discharge port by reciprocating a movable member having a surface on which irregularities are repeatedly formed in the predetermined direction by a driving device. Part of the reciprocating motion in the predetermined direction, stirring the printing agent in the printing agent container of the filling member,
The viscosity of the printing agent in the printing agent container is prevented from increasing. Here, since the direction of the irregularities repeatedly formed on the surface of the movable member and the direction of the reciprocating motion of the movable member are the same, the movement of the printing agent by the movable member is performed favorably, Stirring properties are improved.

According to a fourth aspect of the present invention, in the printing material filling apparatus according to the second or third aspect, irregularities are repeatedly formed on an inner wall surface of the printing material containing portion of the filling member along a moving direction of the movable member. It is characterized by having. In this printing agent filling device, when the movable member is driven in the printing agent storage section of the filling member, the printing agent near the movable member tends to move together with the movable member. On the other hand, the printing agent in the vicinity of the inner wall surface of the printing agent container is hard to move due to the unevenness of the inner wall surface. In a region where the printing agent near the movable member and the printing agent near the inner wall surface of the filling member are in contact with each other, the two are mixed and the printing agent is stirred.

According to a fifth aspect of the present invention, in the printing agent filling apparatus of the second or third aspect, the unevenness of the inner wall surface of the filling member is as follows:
It is characterized by being formed using a groove, a rib or a combination thereof extending along the direction of movement of the printing agent from the supply port toward the discharge port. In this printing material filling apparatus, the printing material that travels from the supply port of the filling member to the discharge port moves along a groove, a rib, or a combination thereof that extends in the printing material movement direction formed on the inner wall surface of the filling member. Therefore, the flow of the printing agent toward the discharge port is not easily blocked by the inner wall surface.

According to a sixth aspect of the present invention, in the printing agent filling apparatus of the second or third aspect, the driving device is configured to drive the movable member based on a load torque of the movable member. Is what you do. In this printing material filling apparatus, the printing material is driven such that the load torque is constant based on the load torque of the movable member that changes according to the viscosity of the printing material in the printing material container, and the printing material is The viscosity of the printing agent in the storage section is maintained at a predetermined viscosity.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to a printing agent used when batch forming bump electrodes made of cream solder as a printing agent on a wafer on which a large number of semiconductor elements (semiconductor chips) as printing objects are formed. Filling device (hereafter,
It is called “filling device”. An embodiment applied to (1) will be described.

FIG. 1A is a side view of a filling device according to this embodiment, and FIG. 1B is a front sectional view of a filling member and the like used in the filling device. The filling device includes a filling member 1 that comes into contact with a printing mask (hereinafter, referred to as a “stencil mask”) 10 on which a printing pattern including through holes is formed.
And cream solder as a conductive paste
And press-fitting means for press-fitting. The filling member 1 includes a printing agent container 1a for accommodating the cream solder 50, a discharge port 1b formed at a portion that comes into contact with the stencil mask 10, and a supply for supplying the cream solder 50 to the printing agent container 1a. It has a mouth 1c. The printing agent storage section 1a and the discharge port 1b are formed so as to extend in an intersecting direction (A direction in the figure) that intersects a direction in which the cream solder is moved (B direction in the figure). The outlet 1b
Is set to be sufficiently larger than the through hole of the stencil mask. A plurality of the supply ports 1c are formed along the cross direction so that the cream solder is uniformly supplied into the printing agent container 1a.

The filling member 1 is integrally formed of an elastic material (for example, an elastomer resin such as urethane rubber or silicone rubber). Further, the thickness of the wall 1d near the discharge port 1b is made smaller than that of the other portions, thereby making it easy to follow the surface irregularities of the stencil mask. As a result, the printing agent storage section 1a stores the wafer 51 to be printed.
And it can be closed with the stencil mask 52 to form a closed space.

Further, the printing agent accommodating portion 1a of the filling member 1 is provided.
Is provided with a stirring means for moving a part of the cream solder 50 which is going to move from the supply port 1c toward the discharge port 1b in a direction different from the moving direction of the cream solder and stirring. This stirring means is composed of a movable member 2 having an uneven surface, and a drive device 3 for reciprocating the movable member 2 in a longitudinal direction (A direction in the figure). The axis of the movable member 2 is supported by walls at both ends in the longitudinal direction of the filling member 1 via bearings (not shown). Also,
The outer peripheral surface of the filling member 1 is formed so that the convex portions 2a are distributed, and has a surface in which irregularities are repeatedly formed in the longitudinal direction. The driving device 3 is attached to one end of the filling member 1 in the longitudinal direction, and can be configured using, for example, a solenoid.

In the driving device 3 for the movable member 2,
The driving of the movable member 2 is controlled so that the load torque of the movable member 2 becomes a predetermined load torque. Since the load torque of the movable member 2 changes according to the viscosity of the cream solder 50 in the printing agent container 1a, the drive control of the movable member 2 allows the printing agent container to be provided without separately providing a viscosity sensor. The viscosity of the cream solder 50 in 1a can always be set to a predetermined viscosity.

The movable member 2 may be a member in which disk-shaped plate members 21 are attached at a predetermined pitch in the longitudinal direction of the shaft body 20 (see FIG. 2A). The movable member is mounted in the printing agent container 1a of the filling member 1 and reciprocated in the longitudinal direction (C direction in the figure). Further, as the movable member, a member whose diameter of the cross-sectional shape 22 orthogonal to the longitudinal direction changes periodically along the longitudinal direction may be used (see FIG. 2B). The movable member is mounted in the printing agent container 1a of the filling member 1 and reciprocated in the longitudinal direction (C direction in the figure). Further, as the movable member, a shaft 23
May be used in which a disk-shaped plate member 24 is attached obliquely at a predetermined pitch in the longitudinal direction (see FIG. 2C). This movable member is attached to the inside of the printing agent storage part 1a of the filling member 1 and rotated in the direction D in the drawing.

As shown in FIG. 3, a groove 1e is formed on the inner wall surface of the filling member 1 so as to extend along the direction in which the cream solder is pushed from the supply port 1c to the discharge port 1b. Due to the groove 1e, irregularities are repeatedly formed on the inner wall surface of the filling member 1 along the direction of reciprocation of the movable member 2, and the cream solder which is to move near the movable member 2 and the Since the two are mixed in a region in the vicinity of the inner wall surface and in contact with the cream solder to be retained, the cream solder can be satisfactorily stirred.
In addition, since the groove 1e extends along the direction in which the cream solder is extruded, the flow of the cream solder toward the discharge port 1b is not easily blocked by the inner wall surface of the filling member 1, and the printing agent is extruded from the discharge port 1b. Can be performed smoothly. Note that, instead of the groove 1e, a convex rib may be formed, or a combination of the groove and the rib may be formed.

The press-fitting means comprises a pressurizing and supplying device 4 for pressurizing and supplying the cream solder 50, a relay member 5 mounted on the top of the filling member 1, and connecting the pressurizing and supplying device 4 to the relaying member 5. And a relay hose 6.
The relay member 5 is provided with a locking portion 1 formed on an upper portion of the filling member 1.
f. A relay housing 5a is formed by the inner wall of the relay member 5 and the upper surface of the filling member 1, and the cream solder 50 in the relay housing 5a passes through a supply port 1c formed in a plurality of lengthwise directions to supply the filling member 1 with the cream solder 50. Printing agent container 1
b. Note that the relay member 5 may be integrally formed with the filling member 1.

As shown in FIG. 4, the cream solder 50 in the cylinder 40 is
One extruded at 1 can be used. In the case of this configuration, by applying a constant pressure to the piston 41, the internal pressure in the printing agent container 1a can be maintained at a constant pressure. Also, as shown in FIG.
2 is fed by a small roller 44 attached to the outer periphery of the rotary roller 43, or the cream solder 50 in a cylindrical transport path 45 as shown in FIG. Alternatively, a material extruded with the above method may be used. Further, a pair of squeezing rollers is attached to the upper part of the flexible bag containing the cream solder, and the pair of squeezing rollers is moved so as to squeeze out the cream solder in the flexible bag. A cream solder may be supplied under pressure.

The printing of cream solder using the filling device having the above-described structure is performed as follows. First, as shown in FIG. 1B, the stencil mask 3 is positioned so that the through-hole 3a is located on the conductive pad 2a of the wafer 2. Then, the cream solder 50 is press-fitted into the printing material accommodating portion 1a of the filling member 1 by the press-fitting means, and the printing material accommodating portion 1a of the filling member 1 is closed by the wafer 51 and the stencil mask 52 to form a sealed space. When the filling member 1 is moved in the direction of arrow B in this state, the through holes 52a of the stencil mask 52 are successively press-filled with the cream solder 50. Then, when the stencil mask 52 in which the cream solder 50 is press-fitted into the through holes 52a is separated from the wafer 51 after a predetermined time has elapsed, bump electrodes are formed on the conductive pads 51a of the wafer 51.

As described above, according to the present embodiment, the cream solder 50 in the printing material container 1a of the filling member 1 can be stirred by the reciprocating movable member 2, so that the cream solder 50 in the printing material container 1a can be stirred. High viscosity can be reliably prevented. Therefore, it is possible to form a good bump electrode over time. Further, the cream solder 50 is extruded from the discharge port 1b of the filling member 1 to the stencil mask 52, not by the movable member 2 that stirs the cream solder 50 in the printing agent container 1a, but by the printing agent container 1a. Can be performed by a press-fitting means for press-fitting the cream solder 50 even if the cream solder 50 is continuously extruded.
It is possible to prevent the solder particles, which are the solid components of the cream solder 50, from being separated from the flux, which is the liquid component, without excessively stirring 0.

In the above embodiment, the case where the bump electrodes made of cream solder are collectively formed (printed) on the wafer 1 on which a plurality of semiconductor elements are formed has been described. The present invention can be applied without being limited to the type and the type of printing agent. For example, the present invention can be applied to a case where a bump electrode is formed on a BGA or CSP type package in which a semiconductor chip is molded, or a connector surface-mounted on a substrate, and a similar effect can be obtained. It is. Further, when forming a bump electrode on an electronic component such as a package or a connector, a plurality of electronic components are arranged so that the bump electrode forming surface is located on the same virtual plane, and the bump electrode forming surface of the plurality of electronic components is arranged on the bump electrode forming surface. Batch formation of bump electrodes (printing)
It is also applicable to the case where it does.

In the above embodiment, the case where the printing agent is filled in the printing mask (stencil mask) having the printing pattern including the through-hole has been described. The present invention can also be applied to a case where a printing agent is filled in a printing mask (intaglio mask) having the following.

[0026]

According to the first to sixth aspects of the present invention, the printing agent in the printing agent storage section of the filling member can be agitated by the stirring means, so that the printing agent in the printing agent storage section is reliably prevented from having a high viscosity. can do. Moreover, the printing agent can be pushed out of the printing surface of the stencil mask from the discharge port of the filling member by the press-fitting unit that press-fits the printing agent into the printing agent storage unit instead of the stirring unit that stirs the printing agent in the printing agent storage unit. Therefore, even if the printing agent is continuously extruded, the printing agent is not agitated excessively, and there is an effect that separation of the solid component and the liquid component of the printing agent can be prevented.

In particular, according to the second aspect of the present invention, a part of the printing agent moving from the replenishing port to the discharging port of the filling member is changed by the unevenness of the surface of the movable member to the direction of movement of the printing agent. Is moved in a different direction to agitate the printing agent, so that it is possible to prevent the printing agent from becoming highly viscous in the printing agent storage portion without hindering the overall movement toward the discharge outlet of the printing agent. There is an effect that can be.

In particular, according to the third aspect of the invention, the printing agent can be favorably moved by the movable member, and there is an effect that the agitation property of the printing agent is improved.

In particular, according to the fourth aspect of the present invention, the printing agent which is to be moved near the movable member and the printing agent which is to be retained near the inner wall surface of the filling member are mixed in a region where the two are in contact with each other. Therefore, there is an effect that the printing agent can be favorably stirred.

According to the fifth aspect of the present invention, since the flow of the printing agent toward the outlet is not easily blocked by the inner wall surface of the filling member, the printing agent can be smoothly pushed out from the outlet. This has the effect.

According to the present invention, the viscosity of the printing agent in the printing agent container can be determined by the predetermined viscosity even if the viscosity of the printing agent in the printing agent container is not detected by a separately provided viscosity sensor. There is an effect that can be maintained.

[Brief description of the drawings]

FIG. 1A is a side view of a filling device according to an embodiment of the present invention. (B) is sectional drawing of the filling member used for the same filling apparatus.

FIGS. 2A to 2C are perspective views of a movable member according to a modification.

FIG. 3 is a partial cross-sectional perspective view of the filling member.

FIG. 4 is a schematic configuration diagram of a pressurizing supply device of a press-fitting unit.

FIGS. 5A and 5B are schematic configuration diagrams of a pressure supply device according to a modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filling member 1a Printing agent accommodation part 1b Discharge port 1c Supply port 1e Groove 2 Movable member 2a Convex part of movable member surface 3 Drive device 4 Pressurizing supply device 40 Cylinder 41 Piston 5 Relay member 5a Relay accommodation portion 6 Relay hose 50 Cream Solder 51 Wafer 52 Stencil mask 52a Through hole

Claims (6)

[Claims] 1. A printing agent filling device for filling a printing agent into a through-hole or a concave portion of a printing mask, wherein the printing agent is formed in a printing agent storage section for storing the printing agent and a portion in contact with the printing mask. And a replenishing port for replenishing the printing agent container with the printing agent, and a part of the printing agent moving from the replenishing port in the printing agent container toward the discharging port. Press-fitting means for using a filling member having a stirring means for moving the printing agent in a direction different from the moving direction of the agent to stir the printing agent, and for press-fitting the printing agent into the printing agent container from the supply port of the filling member. Is provided independently of the stirring means. 2. The printing material filling apparatus according to claim 1, wherein the stirring means comprises: a movable member having an uneven surface;
And a driving device for driving the movable member. 3. The printing material filling apparatus according to claim 2, wherein the movable member has a surface on which irregularities are repeatedly formed in a direction intersecting a moving direction of the printing material from the supply port to the discharge port of the filling member. A printing material filling apparatus, characterized in that a movable member having: is provided so as to be able to reciprocate in a direction intersecting with the moving direction of the printing material. 4. The printing material filling device according to claim 2, wherein the inner surface of the printing material container of the filling member has irregularities repeatedly formed along the moving direction of the movable member. Printing agent filling device. 5. The printing material filling apparatus according to claim 2, wherein the unevenness of the inner wall surface of the filling member extends along a direction in which the printing material moves from the supply port toward the discharge port. Or a printing agent filling device characterized by being formed using those combinations. 6. The printing material filling apparatus according to claim 2, wherein the movable member is driven so that the load torque of the movable member is constant.